Sealing sheath for prosthetic liner and related methods

ABSTRACT

The sealing sheath is for use with a prosthetic socket and associated liner. The sealing sheath includes a textile tube for surrounding at least a portion of a liner that is configured to wear on a residual limb. An annular seal, e.g. an elastomeric or silicone seal, is positioned adjacent a proximal end of the textile tube and continuously extends from an inside of the textile tube configured to be adjacent the liner, through the textile tube to an outside thereof configured to be adjacent an inside of the prosthetic socket. The annular seal may include a first wing on an inside of the textile tube configured to be adjacent the liner, a second wing on an outside of the textile tube configured to be adjacent an inside of the prosthetic socket, and a base connecting lower ends of the first and second wings to define a v-shaped cross-section of the annular seal.

FIELD OF THE INVENTION

The present invention relates to the field of prosthetic and orthoticliners and/or sleeves (i.e. skin-socket interface liners and sleeves),and more particularly to custom and production (“off the shelf”)prosthetic liners, sleeves, and associated methods.

BACKGROUND OF THE INVENTION

Liners provide a soft, flexible interface between a residual limb of anamputee and a hard socket to which a prosthetic device is secured. Suchliners are typically made of an elastomer material such as silicone.Such liners may also be used in connection with orthotic devices.Suspension sleeves are a flexible tube used to secure the prostheticdevice to the patients limb. The sleeve may be a sealing sleeve, or asuspension sleeve. Both types start on the prosthetic device and finishon the patients limb. Supportive sleeves can be used in an orthoticdevice to support a joint or limb of a patient.

Prosthetic suspension liners are described in prior patents, and may befabricated of elastomer or rubber materials, and are used to cushion apost-operative stump or residual limb with respect to a prosthesis thatis installed over the residual limb and coupled to the liner, e.g. by aconventional locking device.

Such liners should conform closely with the residual limb, accommodateall surface contours and sub-surface bone elements of the residual limb,and provide a comfortable cushion between the residual limb and the hardsocket of the prosthesis that is to be fitted over the residual limb.Various silicone rubber or elastomer materials are used for suspensionliners. Such elastomer materials having an appropriatehardness/softness, elongation, tensile, and other properties, such asbio-inertness (resulting in no skin reaction), have been successfullyused for suspension liners.

The elastomer forming the liner or sleeve frictionally engages andremains attached to the skin of a residual limb so that the limb isretained within the prosthetic socket in a comfortable, non-irritatingmanner. For example, liners may be used for any level of amputation bothupper and lower limb.

When an amputee walks air inside the socket allows the socket to fallaway from the amputee during swing phase (the time the prosthesis is inthe air between steps) causing an accelerated impact of the residuallimb and the bottom of the socket when the heel hits the floor. Byremoving the air in the socket the prosthesis is held closer to theresidual limb during swing phase reducing the accelerated impact at heelstrike. There are various ways to seal the proximal portion of thesocket and the liner that covers the amputee's residual limb. The mostcommon is the use of a sealing sleeve. The sealing sleeve is attached tothe outside of the socket and extends up onto the amputee's limb usuallysealing on the liner.

Problems with sealing sleeves include, but are not limited to,punctures, bunching behind the knee, restricted knee flexion, andtearing along the brim of the socket.

U.S. Pat. No. 7,025,793 to Egilsson is directed to a seal but it isattached directly to the liner, which does not allow for optimalplacement of the seal. The design configuration may not allow for highervacuum sockets. Another existing seal is disclosed in U.S. Pat. No.7,144,429 to Carstens. The seal arrangement includes a cuff-like basewith a sealing lip on an outside thereof. The lip has two flaps to sealon both the liner and inner socket wall but nothing to hold the base inplace, which may allow for the possibility of migration of the sealproximally during donning of the liner, compromising the seal.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a more reliable sealfor use with prosthetic sockets and associated liners.

This and other objects, advantages and features in accordance with thepresent invention are provided by a sealing sheath for use with aprosthetic socket and associated liner, the sealing sheath including atextile tube for surrounding at least a portion of a liner that isconfigured to wear on a residual limb. An annular seal, e.g. anelastomeric or silicone seal, is positioned adjacent a proximal end ofthe textile tube and continuously extends from an inside of the textiletube configured to be adjacent the liner, through the textile tube to anoutside thereof configured to be adjacent an inside of the prostheticsocket.

The textile tube may include a closed distal end opposite the proximalend which is open. The textile tube may define a wicking layer fordistributing vacuum within an area defined between the liner and theprosthetic socket and sealed by the annular seal.

The annular seal may comprise a first wing on an inside of the textiletube configured to be adjacent the liner, a second wing on an outside ofthe textile tube configured to be adjacent an inside of the prostheticsocket, and a base connecting lower ends of the first and second wingsto define a v-shaped cross-section of the annular seal. The first wingmay extend through the textile tube from the inside to the outsidethereof. The base may extend through the textile tube from the inside tothe outside thereof. The second wing may have a tapered width from thelower end to an upper end thereof.

Objects, advantages and features in accordance with the presentinvention are also provided by a method of making a sealing sheath foruse with a prosthetic socket and associated liner, the method includingproviding a textile tube for surrounding at least a portion of a linerthat is configured to wear on a residual limb, and forming an annularseal adjacent a proximal end of the textile tube and continuouslyextending from an inside of the textile tube configured to be adjacentthe liner, through the textile tube to an outside thereof configured tobe adjacent an inside of the prosthetic socket.

Forming the annular seal may comprise forming a first wing on an insideof the textile tube configured to be adjacent the liner, a second wingon an outside of the textile tube configured to be adjacent an inside ofthe prosthetic socket, and a base connecting lower ends of the first andsecond wings to define a v-shaped cross-section of the annular seal. Thesecond wing may be formed with a tapered width from the lower end to anupper end thereof. Also, forming the annular seal may include the use ofa mold having a body for holding the textile tube, and body portionscorresponding to a shape of the annular seal. As such, forming theannular seal may further comprise providing silicone in the mold to fillthe body portions and define the annular seal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a vacuum socket and liner, and asealing sheath and seal in accordance with features of the presentinvention.

FIG. 2 is an enlarged view illustrating details of the sealing sheathand seal of FIG. 1 between the socket wall and liner.

FIG. 3 is a schematic diagram illustrating various steps in anembodiment of a method for making the sealing sheath of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings in which preferred embodiments ofthe invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout and prime notations are usedin alternate embodiments.

The following description refers to, by example, a liner associated withthe knee, however, the features of the invention apply to liners andsleeves for use with any limb/joint area that may benefit from the useof a sealing sheath as described herein. Features of the presentinvention are directed to a sealing sheath for a prosthetic or orthoticliner or sleeve and associated methods of making and using. Dimensionsof layers in the drawings may be exaggerated for ease of explanation.

Referring to FIGS. 1-2 below, the approach of the present invention willbe described. As discussed above, a conventional sealing sleeve isnormally worn on the outside of the socket and seals on the portion ofthe liner that extends out of the top of the socket. This approachleaves the sleeve exposed to the outside environment, and such exposureis the source of many of the problems associated with sleeves such aspunctures, bunching behind the knee, restricted knee flexion, andtearing along the brim of the socket.

The sealing sheath 10 of the present invention is positioned on theinside of a socket 12 protecting it from the outside environment, and itis placed on a liner 14 at a position, e.g. chosen by the prosthetist bysealing, sewing or otherwise attaching the sheath 10 or textile orfabric tube at a specific distance from the bottom of the uncoveredliner 14, to provide a sufficient sealing area or optimize the sealingarea.

A first wing 22 of the v-shaped annular seal 20 is against the uncoveredliner 14 and a second wing 24 is positioned against the inner socketwall 12. As a one-way expulsion valve 30 in the distal portion of thesocket 12 (or any other evacuation approach) evacuates air, by eithermechanical or electrical means, a vacuum is created beneath the level ofthe seal 20. The sheath 10 or fabric tube holds the seal 20 in theproper position on the uncovered liner 14 as the amputee inserts thelimb into the socket 12. The higher the force of the vacuum the moresecurely the wings 22/24 of the seal are held against the liner 14 andinner socket wall 12.

Since the seal 20 is preferably positioned below the joint, e.g. knee,joint flexion is not inhibited and the there is no extra material aroundthe joint to cause any bunching. Punctures and tearing are also reducedor eliminated because the seal is inside the socket, and the tearingthat occurs from movement at the knee may also be reduced or eliminated.

As illustrated in the enlarged view of FIG. 2, the annular seal 20 mayinclude a first wing 22 on an inside of the textile tube 10 configuredto be adjacent an outer surface of the liner 14. A second wing 24 is onan outside of the textile tube 10 configured to be adjacent an insidesurface of the prosthetic socket 12. A base 26 connects lower ends ofthe first 22 and second 24 wings to define a v-shaped cross-section ofthe annular seal 20. The first wing 22 may extend through the textiletube 10 from the inside to the outside thereof. The base 26 may extendthrough the textile tube 10 from the inside to the outside thereof. Thefirst 22 and second 24 wings may have a tapered width from the lower endto an upper end thereof. Such a tapered seal design, i.e. from bottom totop making the upper edge thinner than the base 26, gives the seal 20more flexibility, allowing the seal more mobility to allow for anyforces during ambulation that would try to pull the seal away from boththe liner 14 and inner socket wall 12. In the present invention, whenvacuum is applied to the underside of the seal 20, the vacuum draws thewings 22/24 of the seal 20 tighter against the socket 12 and liner 14.

The seal 20 is connected, e.g. during molding or curing, to the sheath10 or fabric tube that is separate from the liner 14. This arrangementallows for the sealing sheath 10 to be replaced, e.g. if damaged, at alower cost than that of replacing an entire liner 14. Of course, ifdesired, the sheath 10 or portions thereof could be attached to theliner.

The seal 20 is preferably made of silicone or any other elastomer thatprovides an adequate seal, and protrudes, extends through or isotherwise formed on both sides of the sheath 10 or fabric tube to allowfor a complete seal against the liner 14.

With reference to FIG. 3, the sealing sheath 10 may be made using a male40 and female 46 mold. The male mold 40 is a cylinder with a smallannular indent 42 corresponding to the portion of the seal 20 on theinner portion of the sealing sheath 10 (step A). A section of fabric 44is pulled over the male mold 40 (step B). The female mold 46, e.g.having an annular indent 48 corresponding to the shape of the seal 20,is then placed over the male mold 40 and fabric 44 with indexing on themale mold so the main shape of the seal lines up with the indent 48 inthe male mold 40 (step C). The combination of molds are then injectedwith the appropriate silicone. The fabric 44 will bridge the smallannular indent 42 in the male mold 40 allowing for the silicone to passthrough the fabric and ensuring a silicone layer on both sides of thefabric.

The sheath material 10 or fabric tube may also act as a vacuum wickbelow the seal 20 ensuring that the seal is held against the socket 12and liner 14 tightly. Such a fabric tube 10 can also be sewn and trimmedto accommodate any residual limb length. By sewing the fabric tube 10,the clinician or amputee can place the seal at a preferable height onthe liner 14 from the distal end thereof. The fabric tube 10 also stopsthe seal 20 from migrating proximally, or out the top of the socket 12.As discussed above, such migration could cause a loss in vacuum.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is to be understood that the invention is not to belimited to the specific embodiments disclosed, and that modificationsand embodiments are intended to be included within the scope of theappended claims.

1. A sealing sheath for use with a prosthetic socket and associatedliner, the sealing sheath comprising: a textile tube defining an openproximal end; and an annular seal continuously extending from and alongan inside surface of the textile tube, and through the textile tube toan outside surface thereof, the annular seal including a first wingalong on the outside surface of the textile tube, a second wingextending along the outside surface of the textile tube, and a baseconnecting lower ends of the first and second wings adjacent to theoutside surface of the textile tube to define a v-shaped cross-sectionof the annular seal; wherein the textile tube forms outer and innerperipheral surfaces of the sealing sheath in areas beyond the annularseal.
 2. The sealing sheath according to claim 1, wherein the annularseal is positioned adjacent a proximal end of the textile tube.
 3. Thesealing sheath according to claim 1, wherein the textile tube defines awicking layer.
 4. The sealing sheath according to claim 1, wherein thefirst wing, the second wing and the base define a generally v-shapedcross-section of the annular seal.
 5. The sealing sheath according toclaim 1, wherein the second wing has a tapered width from the lower endto an upper end thereof.
 6. The sealing sheath according to claim 1,wherein the annular seal comprises an elastomer seal.
 7. The sealingsheath according to claim 1, wherein the annular seal comprises asilicone seal.
 8. A sealing sheath for use with a prosthetic socket andassociated liner, the sealing sheath comprising: a textile tube havingan open proximal end and a closed distal end; and an annular sealpositioned adjacent the proximal end of the textile tube and comprisinga base continuously extending from an inside surface of the textiletube, through the textile tube to an outside surface thereof, a secondwing extending outwardly from the base and upwardly from the base onlyfrom the outside surface of the textile tube toward the proximal end. 9.The sealing sheath according to claim 8, further comprising: a firstwing extending upward from the base at least and through the textiletube from the inside surface to the outside surface thereof;
 10. Thesealing sheath according to claim 9, wherein the textile tube forms aninner peripheral surface of the sealing sheath in areas beyond theannular seal.
 11. The sealing sheath according to claim 8, wherein thetextile tube defines a wicking layer.
 12. The sealing sheath accordingto claim 9, wherein the first and second wings combine to define av-shaped cross-section defined only along the outside surface of thesealing sheath.
 13. The sealing sheath according to claim 9, wherein thefirst wing extends upwardly beyond an upper end of the second wing. 14.The sealing sheath according to claim 8, wherein the second wing has atapered width from a lower end to an upper end thereof.
 15. The sealingsheath according to claim 8, wherein the annular seal comprises asilicone seal.
 16. A sealing sheath for use with a prosthetic socket andassociated liner, the sealing sheath comprising: a tube having an openproximal end and a closed distal end; and an elastomeric annular sealincluding a base extending from an inside surface of the tube configuredto be adjacent the liner, through the textile tube to an outside surfacethereof configured to be adjacent an inside of the prosthetic socket, afirst wing extending from the base on the outside surface of the tube,and a second wing extending upwardly from the base on the outsidesurface of the tube configured to be adjacent an inside of theprosthetic socket, the first and second wings combining to define av-shaped cross-section located only along the outside surface of thetube with a clearance defined between upper end portions of the firstand second wings.
 17. The sealing sheath according to claim 16, whereinthe base and the first wing extend in proximal and distal directionsalong the inside surface of the textile tube relative to the secondwing.
 18. The sealing sheath according to claim 16, wherein the tube isformed from a textile and defines a wicking layer.
 19. The sealingsheath according to claim 18, wherein the annular seal comprises asilicone seal.
 20. The sealing sheath according to claim 16, wherein thetube forms an inner peripheral surface of the sealing sheath in areasbeyond the annular seal.